Canopy for supporting luminaires



March 31, 1942. M. RUGGIERI 2,

/ CANOPY FOR SUPPORTING LUMINAIRES Filed Jan. 5, 1940 INVENTOR.

, ATTORNEY.

Patented Mar. 31, 1942 UNITED STATES FATE orric CANOPY FOR SUPPORTINGLUMINAIRES Application January 5, 1940, Serial No. 312,505

2 Claims.

This invention relates to improvements in canopies for supportingluminaires.

Heretofore in certain types'of luminaires exposed to extreme changes inweather, frequent failures of the lighting units occurred during orshortly after a period of precipitate weather. It is well known thatluminaires of the closed type which are used particularly for streetlighting, develop high temperatures on the surface of the lamp withinthe fixture. During a rainy period, the luminaire breathes in a certainamount of moisture which is vaporized by the heat and rises to the topof the luminaire fixture and condenses on relatively cooler portionsthereof, forming drops of water heavy enough to cause them to fall uponthe light bulb. These drops are cold in comparison to the temperature ofthe bulb and set up stresses therein which cause the bulb to collapse.

When luminaires are suspended from certain well-known types of brackets,there is a tendency for water to enter the bracket and drain into theluminaire, thereby causing damage to the hot light bulb.

Therefore, it is an object of this invention to provide for a luminairea canopy which will collect water that enters the luminaire through itssupporting bracket or that may be condensed therein and which willdirect the water thus collected to the exterior of the canopy, therebypreventing the water from falling upon the relatively hot bulb withinthe luminaire.

More specifically, it is an object to provide a canopy having acondensation chamber in which water may collect and from which the watermay escape by means of a plurality of drain openings to the exterior ofthe canopy, thereby preventing its contact with a hot bulb beneath thecanopy.

Another object is to provide for a canopy a condensation chamberincluding a plurality of drain openings and a wire-receiving aperturehaving a barrier preventing water in the condensation chamber frompassing through the aperture and causing damage to a bulb below thecanopy.

A further object is to provide for a luminaire canopy, a condensatechamber having a fluted bottom adapted to direct condensate to theexterior of the canopy.

In the drawing: a

Fig. 1 is a vertical view, partly in section, illustrating a luminaireembodying this invention.

Fig. 2 is a fragmentary sectional view taken on the line 22 of Fig. 1.

The drawing discloses a closed typeluminaire comprising a supportingtubular bracket I, a canopy or hood 3, a detachable reflector 4, a glassglobe 5 and a light bulb 6 which is secured to the canopy in anywell-known manner, 11 t shown. i g

The supporting tubular bracket I is conne ed to a supporting structureIA by means of a plate 2A for suspending the luminaire over an area tobe illuminated. The bracket further acts as a conduit for electricalline wires 3A and is provided at its depending elbowed end 2 with athreaded portion 1.

The canopy 3 is cast as an integral unit and comprises a shell 8 havinga support 9 shown by broken lines exteriorly of the lower end of theshell and to which the detachable reflector 4 is held by means of a pairof toggle latches including a bail member 9'. Detail of this toggle isnot given in full since it is in common use and forms no part of thisinvention. A hexagonal portion I0 is provided at the upperend of theshell 8 for engagement by means of a wrench and is provided with acentrally-located threaded aperture II receiving therein the threadedend 2 of the bracket I.

A cylindrical condensation chamber I3 is disposed within the upperportion of the canopy and below the lower end of the aperture H. A pairof drain openings or tubular passageways I4 extend in oppositedirections outwardly through the wall I5 of the chamber and downwardlyat a slight angle relative to a horizontal planethrough the chamber.

The base I6 of the chamber I3 is provided with a wire-receiving apertureIi centrally located therein and disposed in substantially axialalignment with the threaded end of the bracket I. The aperture placesthe chamber It in communication with the lower portion of the luminaireand is adapted to receive the conductor wires 3A for electricalconnection with the light bulb B. An annular barrier portion or collarI8, surrounding the aperture I! and positioned in the chamber I3, isintegrally cast with the base and is adapted to prevent water fromentering the interior of the luminaire. The base is further providedwith a pair of drain flutes I6A which extend radially from the collar !8and terminate in the drain openings I4 as shown.

It is contemplated that the threaded end I of the bracket I should beonly of sufficient length to prevent the end I from contacting with thebase I6. However, if for any reason the threaded end is longer thancontemplated and contacts condensate collecting in the chamber to theholes I4 which will direct such condensate to the exterior of thecanopy. It is, of course, understood that to efiect this result, it isimperative that the outside diameter of the collar I8 must be less thanthe inside diameter of the end I on the bracket I, as clearly indicatedin the drawing.

The upper edge of the hemispherical glass globe is provided with a pairof supports I9 attached on diametrically opposite sides thereof in anywell-known manner, not shown, and now in common use. The globe 5 issecured in firm contact with the depending flanged portion 20 at thelower end of the reflector 4 by means of springs ZI which are hingedlyconnected to the supports I9 and are provided with latching levers 22adapted to engage the catch hooks 23 on the reflector 4. While I haveshown this globe mounting means in some detail, it will be understoodthat it forms no part of this invention and may be replaced with anyother latching arrangement without departing from the spirit of thisinvention.

When weather conditions are such that air in the vicinity of theluminaire contains a comparatively large amount of moisture, thismoistureladened air is drawn into the interior of the luminaire by abreathing action of the luminaire due to the expansion and contractionof the air within the luminaire. This variation in the density of theair in the luminaire may result from several causes, one of which may bethe heat emanating from the light bulb 6. When heat is emanating fromthe light bulb, th adzjacent air is heated and caused to expand. Thisexpanded air escapes through the drain openings I4, or through thejoints between the globe and the reflector and joints between thereflector and the canopy. When the luminaire is electricallydisconnected, the unit cools and the air within the unit contracts,thereby causing the air surrounding the luminaire to enter through theopenings I4 or other apertures. Excess moisture in the air entering theluminaire Will be condensed on any relatively cool surface andultimately collect in the bottom of the globe 5.

When the luminaire is again electrically connected for operation, theconfined air expands and the water previously collected at the bottom ofthe globe is vaporized by the heat emanating from the light bulb. Thisvapor rises to the top of the fixture and enters the chamber I3 where itis condensed in the condensation chamber and pipe bracket I because oftheir relatively cooler condition.

The condensate accumulates on the walls of the chamber and the pipebracket and ultimately the base, the flutes ISA will serve to conductflows to the base I6 of the chamber and escapes therefrom through thedrain openings I4.

It may-be noted that to insure that the water falling from the lower endof the bracket I will enter the chamber I3 rather than pass to theinterior of the luminaire, the outer diameter of the barrier I8 is lessthan the inner diameter of the end I.

It is further noted that during a rainy period water may enter thebracket I between the plate 2A and the support IA. This rain water willfollow the walls of the bracket; and fall from the depending end 2 ofthe bracket directly into the chamber I3 from which it then escapes tothe exterior of the luminaire through the openings I4.

It will be obvious from the foregoing that if the barrier I8 and holesI4 were not provided, condensate collecting in the pipe bracket I andcanopy 3 would remain within the luminaire and possibly drop upon thelight bulb 6 and under such conditions, the cool condensate would set upstresses in the bulb, when the latter was hot, tending to destroy it.

Therefore, it may be seen that the objects of this invention have beenaccomplished by providing for a luminaire a canopy having a condensationchamber provided with a plurality of drain openings and a wire-receivingaperture having a water barrier at its chamber end, whereby undesirablewater vapor entering the luminaire may be effectively condensed,collected and expelled to the exterior thereof Without causing damage tothe light bulb below.

I claim:

1. As a new article of manufacture, a canopy for luminaires, said canopybeing of a one-piece casting and comprising a shell portion ofrelatively thin wall formation and a head at the upper end of the shellof increased thickness, said head having a shallow horizontal chambertherein defining top, bottom and side walls, the top wall of the chamberhaving a central threaded opening therein of less diameter than saidchamber, the bottom wall of the chamber being of substantially the samethickness as the shell portion and having a central aperture therein ofless diameter than said threaded opening and surrounded by an upstandingshort tubular boss within the chamber, said head having radial anddownwardly inclined drain passages in the side walls thereof formingcommunication between said chamber and the exterior of said canopy, thelower sides of the inner ends of the passages being in the plane of thetop face of the bottom wall of the chamber.

2. A new article of manufacture as set forth in claim 1, wherein the topface of the bottom wall has radial grooves co-extensive with said drainpassages.

MICHAEL RUGGIERI.

